Contamination of blood and blood components with infectious microorganisms or pathogens creates a serious risk for patients who receive blood or blood components via blood transfusions. Infectious microorganisms or pathogens, include, but are not limited to, viruses, bacteria, bacteriophages, fungi, blood transmitted parasites, and protozoa. Examples of transfusable blood or blood components may include whole blood, packed red blood cells, white blood cells, platelets, and plasma, just to name a few. To combat the contamination problem, blood and blood components can be decontaminated using pathogen inactivating agents or photosensitizers which, when activated, inactivate pathogens within the blood or blood components without destroying the biological activity of the blood or blood components.
Pathogen inactivation agents which may be useful for decontamination include the class of photosensitizers known in the art to be useful for inactivating microorganisms. U.S. Pat. No. 6,277,337 discloses a method and apparatus for inactivation of biological contaminants using photosensitizers and is also hereby incorporated by reference for all that it discloses.
A “photosensitizer” may be defined as any compound which absorbs radiation of one or more defined wavelengths and subsequently transfers the absorbed energy to an energy acceptor. Such photosensitizers may be activated by the application of electromagnetic spectra (e.g. light or photoradiation) to inactivate pathogens with which they may interact. Additionally, U.S. Pat. No. 6,258,577 discloses a method and apparatus for inactivation of biological contaminants using endogenous alloxazine or isoalloxazine photosensitizers and is hereby incorporated by reference for all that it discloses.
Decontaminating blood or blood components may be done by mixing an effective amount of a photosensitizer with the fluid to be decontaminated and then exposing the fluid to an amount of photoradiation at an appropriate wavelength sufficient to activate the photosensitizer and allowing the activated photosensitizer to inactivate at least some of the pathogens contained within the fluid. The wavelength of light used may depend on the photosensitizing agent selected. The light source(s) may provide light in the visible range, the ultraviolet range, or a mixture of light in both the visable and ultraviolet ranges. U.S. Pat. No. 6,843,961 discloses the reduction of contaminants in blood and blood products using photosensitizers and peak wavelengths of light and is hereby incorporated by reference for all that it discloses.
The fluid to be decontaminated may be flowed through an entry port into a photopermeable bag or fluid container. The term “photopermeable” means that the material of the container is adequately transparent to photoradiation of the proper wavelength for activating the photosensitizer. The fluid containers may contain a number of ports which provide access to the interior of the container. Such ports are typically manufactured, at least in part, out of polymeric materials, which are usually more rigid than the main body portion of the fluid container.
During pathogen inactivation, a portion of the fluid to be inactivated may become trapped or remain within one or more of these ports. One problem with these ports is that they may be constructed from a different material, or of the same material having a different thickness, than the main body portion of the fluid container, resulting in varying thicknesses for photopermeability. Another problem with these ports is that they may contain a larger volume of fluid than can be inactivated by a given exposure to the photoradiation. Consequently, fluids trapped within these port paths during pathogen inactivation may still contain infectious pathogens after the inactivation process is completed. These infectious pathogens may then reenter the otherwise decontaminated fluid, recontaminating the fluid.